Abstract
The molecular mechanisms of plant growth and development have been analyzed in detail during the past years. The critical role of a plant-specific family of GRAS domain proteins in these processes has become apparent. In this review we highlight the importance of DELLA proteins in gibberellic acid (GA) and light signaling, the regulation of root patterning by SCR-SHR interactions and the requirement of two GRAS proteins from legumes, NSP1 and NSP2, for root nodule symbiosis. We discuss common and distinct molecular mechanisms underlying GRAS protein function and emphasise new discoveries regarding their function as transcription factors and the role of protein movement in refining their mode of action.